Abstract
To identify genes involved in hormone secretion and tumorigenesis, we compared genes in a null cell adenoma without hormone secretion and in a pituitary adenoma producing only TSH protein. At surgery, tissue was removed and frozen from two patients with null cell adenomas: two patients with TSH-producing pituitary adenomas, and one patient with a normal pituitary (as a control). Serial sections of each tissue were prepared, and tumor cells were isolated using laser capture microdissection. Total RNA was amplified using the T7 promoter and analyzed by DNA microarray. TIMP, co-expressed with MMP and involved in tumor growth, and cyclin B 1, involved in M phase cell cycle regulation, were identified as genes involved in tumorigenesis. Additional genes specific for TSH-producing pituitary adenomas were also identified: transthyretin, which plays a role in fibrous tissue formation; fibroblast growth factor, which is involved in growth hormone, prolactin, and TSH hormone secretion; CSH1, which regulates proteins involved in growth hormone and prolactin hormone secretion; forkhead box N4, which is a major transcription factor in the development and metabolism; and programmed cell death 6 interacting protein, which is involved in programmed cell death.
